Answer:
ego
Step-by-step explanation:
Sigmund Freud was an Austrian who founded the Psychosexual Stages of Development. According to him, the human personality depends on three elements: id, ego and superego.
The element that is associated with reason is the "ego." It develops from "id," which is fueled by the pleasure principle. The ego aids the id to express its impulses in accordance to what is accepted in the society. If the "id" acts immediately without thinking, the "ego" thinks carefully before acting. It allows a person to do things appropriately.